Field of the Invention
The present invention relates to a lithography apparatus and an article manufacturing method.
Description of the Related Art
An exposure apparatus, an imprint apparatus, or the like can be given as a lithography apparatus which transfers the pattern of an original to a substrate. The exposure apparatus is an apparatus which transfers, as a latent image, the pattern of the original to a photoresist (material to be transferred) applied or arranged on the substrate. A resist pattern is formed by developing the photoresist in which the latent image has been formed. The imprint apparatus is an apparatus which forms the pattern of an imprint material (material to be transferred) applied or arranged on the substrate by curing the imprint material in a state in which the original is in contact with the imprint material using the original.
In the lithography apparatus such as the exposure apparatus or the imprint apparatus, if particles are attached to, for example, the substrate, the original, and/or the material to be transferred, an error may occur in a pattern to be formed. Particles in a chamber of the lithography apparatus may enter from the outside of the chamber, or may be generated in the chamber by, for example, the friction between machine elements or the friction between the machine elements and the substrate or the original. Alternatively, the particles may be generated by the material to be transferred.
A boundary layer exists between an airflow and the surfaces of members such as the substrate and the original. If particles which move along the airflow deviate from the flow line of the airflow, the particles enter the boundary layer. Influences on the particles such as a gravity, Brownian diffusion, and static electricity become relatively large inside the boundary layer. Owing to these, the particles may be attached to the surfaces of the members. The attaching forces of the particles to the surfaces of the members are extremely weak, and thus the particles can easily be separated from the surfaces of the members by an external stimulus (a static electricity, airflow, or vibration). The particles separated from the surfaces of the members arranged near the substrate or the original may be attached to the substrate, the original, and/or the material to be transferred.
Patent literature 1 is about an imprint apparatus, and describes an arrangement including a main convex structural part and a sub convex structural part in a mold (original) to trap foreign substances (particles) to the sub convex structural part by charging the sub convex structural part.
In an approach of setting a part of the original as a trapping part and trapping the particles by charging the trapping part like the invention described in patent literature 1, the trapping part which has trapped a large amount of the particles can be a particle source. For example, when a charged state is canceled for some reason, and even when the charged state is not canceled, the particles can be separated from the trapping part and set free by applying a stimulus such as a static electricity, an airflow, or a vibration. Further, as in patent literature 1, if the part of the original is set as the trapping part, the particles can be separated from the trapping part when operating the original. The particles separated from the trapping part may directly be attached to a substrate or the original, or may temporarily be attached to a peripheral member, and then be separated again, resulting in being attached to the substrate or the original.
[Patent Literature 1] Japanese Patent Laid-Open No. 2014-175340
[Non-Patent Literature 1] Masuda, S., Fujibayashi, K., Ishida, K., and Inaba, H., Electric Engineering in Japan, 92, 9 (1972).
[Non-Patent Literature 2] C. I. Calle, J. L. McFall, C. R. Buhler, et al., Proc. ESA Annual Meeting on Electrostatics 2008, Paper O1.